1. Field of the Invention
The invention relates to tube couplings and in particular to tube couplings having a sleeve permanently joined to the tube as by welding.
2. Description of the Prior Art
In one conventional form of tube coupling, the tube end is sealingly coupled to the fitting body by means of a sleeve attached to the tube end as by welding. The sleeve, in turn, is sealingly engaged with the fitting body as a result of a force application effected by a nut threaded to the body. In welding the sleeve to the body, a weld bead is formed at the outer end of the sleeve sealingly joining the sleeve thereat to the tube end which projects into the sleeve outer end. In the known fittings of this type, a problem has arisen from time to time in that the weld bead interferes with the removal of the nut from the body causing substantial difficulty in disconnecting the tube from the body when desired.